Single-stage coupled-inductor sepic-type HB-LED driver with soft switching for universal line input (Q1954963)

Summary: We propose a single-stage Sepic-type high brightness LED driver for universal line input to perform power factor correcting and LED dimming. In the driver, a coupled inductor is introduced to replace with two separate inductors to lower volume and cost. A soft-switching cell is embedded into the driver to obtain zero-voltage switching (ZVS) feature so as to furthermore improve driver efficiency. Mathematical derivation and detailed discussion is presented. A prototype is designed, analyzed and implemented, which demonstrates the feasibility of the driver and verifies the theoretical analysis.